Use of MMIC (microwave monolithic integrated circuit) amplifiers facilitates miniaturization of radar devices and communication equipment.
An MMIC amplifier can be implemented by using e.g. a wafer in which a nitride-based semiconductor layer is provided on a SiC or Si substrate.
However, MMIC provided in a nitride-based semiconductor layer formed on a SiC substrate (AlGaN/GaN/SiC) has low capacitor breakdown voltages and is expensive. MMIC provided in a nitride-based semiconductor layer formed on a Si substrate (AlGaN/GaN/Si) is insufficient in heat dissipation performance for heat generated from the semiconductor element.